About HD 202931
HD 202931 is a trash star. It sits in the constellation Mic, shines at apparent magnitude 8.41 and has spectral type G5.
Its spectrum reads G5 — a G-type star: the very same spectral class as our own Sun.
Trash star 11 EP
HD 202931
RA 320.0274° · Dec -34.5937° · star
Score breakdown
· 2 badgesTrash 15 pts → Common
- Sun-like G-type star +8
- Star +3
Total score 11
4 more points to reach Common.
Badges
- Star · +3
- Sun-like G-type star · +8
Trivia
Hard to believe
- True brightness. It pours out about 3.7 million times as much light as the Sun. It only looks ordinary because it is so far away.
What it actually is
- Spectral class. Its spectrum reads G5 — a G-type star: the very same spectral class as our own Sun.
Find it in the sky
- How to spot it. At magnitude 8.4 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Microscopium.
- Southern sky. It rides the southern half of the sky — an easier target the further south you are.
- Best time of year. It stands highest in the middle of the night around August — that's when to go looking.
Its true colour
- Its true colour. Measured through blue and visual filters it comes out orange (B−V 0.9) — cooler than the Sun, and the kind of star that burns steadily for tens of billions of years.
- Why no green stars. No star ever looks green: a surface hot enough to peak in green also floods out plenty of red and blue, and your eye blends the mixture back to white.
By the numbers
- Surface temperature. Its colour puts the surface at roughly 4900 K, against the Sun's 5778 K.
Properties
- absmag
- -11.59
- bv
- 0.938
- constellation
- Mic
- luminosity
- 3767037.9898
- mag
- 8.41
- name
- HD 202931
- spect
- G5
How to see it
Look for HD 202931 in the constellation Mic. At apparent magnitude 8.41, it is an easy target for binoculars.
Like any astronomical target, HD 202931 is best seen from a dark site away from city lights, and when it is above the horizon depends on your latitude and the time of year. The visibility panel above works out tonight's viewing window for your saved location.
Why HD 202931 is a trash star
HD 202931 scores 11 points on Spacedle's rarity scale, which places it in the trash tier. Another 4 points would lift it into a rarer tier.
That score comes from 2 science badges — Star and Sun-like G-type star — each earned for a real, measurable property of the object. Rarity on Spacedle is never random: the more remarkable an object's astrophysics, the more badges it collects, the higher it scores, and the rarer it ranks.